32 Year NEET Previous Year Questions: Coordination Compounds - 1 - NEET MCQ

Potash alum K₂SO₄ .Al₂ (SO₄)₃ 24H₂O is a double salt.

According to VSEPR theory, a molecule with six bond pairs must be octahedral.

IUPAC name is potas sium trioxalatoaluminate (III).

It is optically active when two Cl atoms are in cis position.

In the formation of a coordinate bond, the ligands donate a pair of electrons to the metal atom. Futher nitrogen and oxygen has great tendency to donate the pair of elctrons in most of  the compounds. Therefore both nitrogen and oxygen are common donor atoms in ligands.

Among the following, the compound that is both paramagnetic and coloured, is [1996]

Chlorophyll may be considered to be an organometallic compound because it contain metal carbon bond.

Pt (NH₃)₂ Cl₂ is a disubstituted complex and shows only cis-& trans-isomers

[Co(NO₂)₃ (NH₃)₃]

Possible geometrical isomers

Total geometrical isomers = 2

The total number of isomers for the complex compound

These four isomers are

The isomer [Cu (NH₃)₂ Cl₂][Pt (NH₃)₂ Cl₂] does not exist due to both parts being neutral.

We know that IUPAC name of [Pt (NH₃)₃ (Br) (NO₂)Cl]Cl is triamminebromochloronitroplatinum (IV) chloride.

As it forms two moles of silver chloride thus it has two moles of ionisable Cl.

In [Fe(CO)₅] Iron exist in zero oxidation state

As in [NiCl₄]^–2 Chloride ion being a weak ligand is not able to paired the electron in d orbital.

In [Cr (NH₃)₆]Br₃, Cr is in +3 oxidation state etc.

presence of three unpaired electrons it is paramagnetic.

Complex Co(en)(NH₃)₂Cl₂]Cl will have four different isomers.

(i) Geometrical isomers

(ii) Optical isomers

[Cr(SCN)₂(NH3)₄]²⁺ has the maximum number of isomers (geometrical + linkage). [Ni(en)(NH₃)₄]²⁺, [Ni(C₂O₄)(en)₂] and [Co(NH₃)₄Cl₂] have 2 geometrical isomers each.

The complex ions which give maximum ion in solution exhibit maximum ionic conductivity

(CO) carbonyl group being a strong ligand paired all electrons present in d orbital of Ni.
Hence form dsp² hybrid orbitals and hence the shape of molecule is square planar.
In Ni(CO)₄ complex, Ni will have 3d¹⁰ configuration. It has tetrahedral geometry but diamagnetic as there are no unpaired electrons.

[Co(CO) ₅ NH₃]²⁺ . In this complex. Coatom attached with NH₃ through σ bonding with CO attached with dative π-bond.

Cr³⁺ has 4sº 3d³ electronic configuration with 3 unpaired electrons, hence paramagnetic.
In other cases pairing of d-electrons take place in presence of strong field ligands such as CO or CN^–.
In Cr(CO)₆ molecule 12 electrons are contributed by CO group and it contain no odd electron

Chloro diaquatriammine cobalt (III) chloride is [CoCl(NH₃)₃(H₂O)₂]Cl₂

Copper sulphate react with KCN to give white ppt of Cu(CN)₂ and cyanogen gas. The insoluble copper cynaide dissolve in excess of KCN and give soluble potassium cuprocyanide

MA₃ B₃ – 2 geometrical isomers
MA₂ B₄ – 2 geometrical isomers
MA₄ B₂ – 2 geometrical isomers
The complexes of general formula Ma₆ and Ma₅b octahedral geometry do not show geometrical isomerism.

IUPAC name of sodiumnitroprusside Na₂[Fe(CN)₅NO] is sodium pentacyanonitrosoyl ferrate (III) because in it NO is neutral ligand.
Hence 2×O.N. of Na + O.N. of Fe + 5×O.N. of CN       1×O.N. of NO = 02×(+1) + O.N. of Fe + 5 ×(–1) +1×0 = 0
O.N. of Fe = 5 – 2 = +3,  
Hence ferrate (III)

Cohere is in +3 oxidation state

Unpaired electrons  = 4 and sp³d² hybridisation and octahedral shape.

π bonded organometallic compounds is indicated by the greek latter 'η' with a number.
The prefixes η², η⁵ and η⁶ indicate that 2, 5 and 6 carbon atom are bound to the metal in the compound.(CH₃)₄Sn does not involve any pi (π) bond formation. This is a π bonded organometallic compound